• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.4
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• pp.147-155
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• 2007

Mobile air conditioning systems work under widely changing operating conditions. To understand the system behavior under such dynamic conditions, a test facility that can impose transient loads as well as conducting dynamic measurements is needed. To test mobile air conditioning systems including their dynamic performance under various drive cycle patterns without using full scale vehicles in a wind tunnel, a new test facility, called "dynamic simulator," is described. It can replicate real vehicle operating conditions by interacting with the system being tested based on the measured system performance and subsequently adjusting the air properties returning to the test system based on the results of a numerical cabin model. A new dynamic simulator has been designed, constructed, and verified for performing dynamic tests. It was successful in controlling the temperature and relative humidity of the air returning to the test unit within ${\pm}0.7^{\circ}C$ and ${\pm}4%$ of their respective intended values. The verification test under the New European Driving Cycle demonstrated that detailed transient behavior of the mobile air conditioning system could be measured by using this dynamic simulator.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.161-169
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• 2008

This paper introduces test configuration and operation method for the GPS receiver system under electromagnetic test of KSLV-I upper-stage as a system qualification level and describes performance analysis of the test results. The GPS receiver system has clearly passed the electromagnetic test specifications of component level which is based on MIL-STD-461E through several design changes. Under electromagnetic test as a system qualification level, the GPS receiver system normally operates in spite of electromagnetic interferences with other systems. Performance of the GPS receiver system is also, not degraded on the condition of electromagnetic field incidence and electrostatic discharge. The KSLV-I GPS receiver system, as a result, is verified on the electromagnetic condition of the KSLV-I upper-stage.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.341-344
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• 2009

In this paper, protective function evaluation was conducted to determine the performance and safety of a power conditioning system(PCS) for 1kW residential fuel cell system. It is essential to have a power quality, grid-connection and safety of PCS. Even though it is under 500ms by KGS-A410 standard, it is shown a rapid response time of 25ms from input under-voltage test. In terms of output over/under-voltage test, it is shown 29.15 and 79.4ms. Especially using anti-islanding test, it is shown all times under 100ms for combination cases of real and reactive power. We confirmed a rapid response characteristics and safety of PCS. The results of this evaluation are being used to develop a new test protocols of PCS.

• Journal of Korean Physical Therapy Science
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• v.16 no.4
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• pp.49-57
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• 2009

Background: The purpose of this study was to assess the test-retest reliability of balance measurements in older adults using balance measurement system(Good Balance). Methods: The subjects consisted of 49 female and 20 male in community-dwelling older adults. This study used a repeated-measure design. Each subject completed all the different tests once and they were then repeated with 2 minutes in between. Repeated two-ways analysis of variance(ANOVA), representing two test times and both sexes, was calculated for each of the two dependent variables. Intraclass correlation coefficients(ICCs) were used to assess the test-retest reliability. Results: 1) There was not significant difference between test and retest for mediolateral sway speed and anterioposterior sway speed under conditions of normal standing with eyes open, normal standing with eyes closed and semitandem standing with eyes open. There was not significant difference between males and females for mediolateral sway speed and anterioposterior sway speed under conditions of normal standing with eyes open, normal standing with eyes closed and semitandem standing with eyes open. There were not the interaction effects between genders and test time under three conditions. 2) The reproducibility between test and retest was excellent for anterioposterior sway speed(ICC=.77) under condition of normal standing with eyes open, and for mediolateral sway speed(ICC=.76) and anterioposterior sway speed(ICC=.84) under condition of semitandem standing with eyes open. The reproducibility between test and retest was fair to good for mediolateral sway speed(ICC=.64) under condition of normal standing with eyes open, for mediolateral sway speed(ICC=.63) and anterioposterior sway speed(ICC=.75) under condition of normal standing with eyes closed. Conclusion: Balance tests in older adults using balance measurement system(Good Balance) demonstrated acceptable levels of reliability.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.279-283
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• 2006

The GPS receiver developed by KARI for the satellite launch vehicle should operate under severe dynamic environments such as high acceleration and jerk. Several terrestrial tests including the outdoor centrifuge test are planed in order to verify performances of the GPS receiver before flight. This paper deals with preliminary test results of the GPS receiver using a GPS signal generator before the centrifuge test that is a performance test of the GPS receiver using live GPS satellite signals. Test methods of the GPS receiver for the satellite launch vehicle under high centripetal acceleration and jerk utilizing a GPS signal generator are described. The simulation results are also analyzed in this paper.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.331-337
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• 2015

The power flow analysis of electrified railway is required complicated calculation, because of variable load. Train runs trough rail supplied by electric power therefore, the load value in electrified railway system fluctuates along time. The power flow algorithm in electrified railway system is different from general power system, and the power flow simulation is peformed by the particular simulation software. Powerail is simulation software for analysis of traction power supply system developed by KRRI, in 2008. This consists of load forecasting module, including TPS and time scheduling, and power flow module. This software was verified by measured current under normal feeding condition, however, has not been verified by voltage on the condition of extended feeding. This paper presents the verification of PowerRail based on voltage drop under extended feeding condition. This is performed by comparing simulation result with field test. Field test and simulation is done in commercial railway line.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1138-1143
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• 2011

One of the critical items in radar testing is the ability to evaluate the performance of radar systems under real operational environments. But it takes lots of time and cost to operate real targets and analyze the test results due to a large amount of data based on these complicated environments. In this paper, the Radar Simulative T&E Lab. is introduced, and the test and analysis results of the developing radar for predicting the radar system performance are described in the Radar Simulative T&E Lab. This laboratory could be used to test the far-field characteristics of antenna radiation pattern and to perform an effective radar system test and evaluation using a simulative target generator under a low cost repeating test situation.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.59-64
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• 2007

This study introduces an environmental noise evaluation procedure and results for a wind turbine (W/T) system. Test and evaluation are required by the international standard IEC 61400-11 in the aspect of environmental effect. Test and evaluation are performed on U-50 WT model which is first developed by the domestic W/T manufacturer. W/T test model is under operation in Daekwanryung wind test site. An integrated monitoring system in the test site is utilized for the evaluation. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level are estimated and compared with those of other similar size WT under the wind speeds required by international standard.

• Current Photovoltaic Research
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• v.6 no.3
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• pp.69-73
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• 2018

PV system is consisted with PV module, inverter and BOS(balance of system). To have robustic operation more than 20 years, the expected and guaranteed durability and reliability of products should be met. Almost components of PV system are qualified through IEC standards at test laboratory. But the qualification certificate of product does not ensure long-term nondefective operation. PV module's expected life time is nowadays more than 20 years and annual maximum power degradation ratio would be less than -1%. But the power degradation ratio is basically based on real data more than several years' record. Developing test method for ensuring annual maximum power degradation ratio is very need because there are many new products every month with new materials. In this paper, we have suggested new test method under continuous artificial light irradiation test condition for analyze expected maximum power drop ratio.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.34-38
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• 2005

This paper describes the result of load test of a bogie frame. The purpose of test is to evaluate the safety which bogie frame shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load. Bogie system consist of the bogie frame, suspensions, wheel-sets, a brake system and a transmission system. Among these component, the bogie frame is most significant component subjected to the vehicle and passenger loads. The evaluation method is used the JIS E 4207 specifications throughout the static load test. The test results have shown the bogie frame to be safe and stable under design load conditions.